Three dimensional representation of distant objects has heretofore been hampered by atmospheric effects. The resultant distortion of the reconstructed holograms seriously deters from use of such holograms for serious military applications under achromatic illumination.
Although achromatic "thin" holograms are commercially feasible and volume holograms can be produced under monochromatic illumination, such holograms appear distorted due to optical variations occurring within the various diffraction gratings used within the beam-splitter part of the optical system.
Some early attempts at compensating for such optical variations are described within the following U.S. Pat. Nos. 4,773,719 and 4,786,124 which Patents attempt to increase the diffraction efficiency of the respective diffraction gratings by complex electronic intervention.
It would be advantageous to provide achromatic volume holograms for both military and commercial applications without requiring complex and expensive electronic or optical equipment beyond the apparatus required to construct and record the hologram, per se.
One object of this invention accordingly, is to provide a simple and economical apparatus for developing and recording such achromatic volume holograms.